Pump with cam-controlled plungers



Jan. 4 1927.- 1,612,888

G. SCHNEGGE-BURGER PUMP WTH CAM CONTROLLED PLUNGERS Filed June 25, 1926 J6 H .2o

l VJyi s The accqmpanying Fig. v7 is a v(Patented Jan. 4,' 1927.

GNTHER scnNn-GGENBUBGEB., or BERLIN-Huismus, annimmt. i

ruime wrrn. cm-coNmaoLL-s rLUNGnas.

Application led June 25, 1926, Serial No.

have become non-uniform ,15 tain'a uniform pump delivery by anincrease Apart from.

. of the circumferential speeds.

fthe fact that a satisfactory uniformity of the pump delivery is not attained thereby, there is 'no possibility of sufliciently lubricating `mrthe high-'speed moved parts, so that a wear' and` working disturbances by seizing of the parts makingcontact with each other soon occurred. This results, of course, in a decrease of the working safety of the pump.

The -p'resent invention overcomes these drawbacks by impart-ing to the plungers a uniform speed in dependence upon lawfully -cons't' 1'u cte'd curves and providing means by Jfwhich always a constant number of plungers -discharge into the common pressure conduit.

Furthermore, for attaining a reliable lubrication, -all the moved parts, which-might cause working disturbances by faulty lubrication, are s'et under pressure oil.

drawing illustrates the subject matter of the present invention z Fig.

- 1 is a cross-section throughia star-shaped arrangementof .cylinders,.on the line C-D of Fig. 2, which is a longitudinal section .4U through said arrangement on the line A-'B 'of Fig. 1; Fig. 3 is a side view of part of the non-revoluble cam shaft of the pump, and Fig. 4 is a cross-section throughsaid `shaft on the line E-YF of Fig. 3 (the dotted curve a: designating a cross-section on the liueG-II of Fig. 3) Fig. 5 is afragmentary side view of a modification of said cam shaft, and Fig. 6 is a cross-section through the latter` on the line I--K of Fig. 5;.wh1le fragmentary 4side view of another modification of said cam shaft, and'Fig. 8 is .a cross-section through vthe latteron the line of Fig. -7.' v

In the pump casing lutheplunger drum'2 55 isy radially and axiallymounted by meansvof means being provided for etliciently and 118,572, and in Germany o'tmr a4, 1925..

the covers 3i and 4 `of said casing. The plunger drum is set in'rotation by means of the worm shaft 5 and worm wheel' 6. In. the plunger drum, and in tw parallel planes at. rightangles to the drum axis, a. fuel pump system with the plungers 7 7*, 7 b, 7 is combin'ed with a lubricant pump systemv with the plungers 8. The plungers positively receive' their pressure stroke by their sliding contact with the cam 9 of the non-revoluble cam shaft 10, while the suction stroke is exertedby the cylindrical coil springs 11 acting upon the plungers. The cam curves @-5 and c-d o f the cam shaft are branches of an Archimedean spiral, while b- -c and d-a are circular arcs. In the pump illustrated, for instance, the pressure curves a--b lie within a sector of 180, the circular arc b--c within a sector of 45, the suction curve c-d within a sector of the circular. arc d-a within a sector of 45. With a star-shaped arrangement of four cylinders at right angles to one another, thus, in any position of the plunger drum always one plunger exerts the suction stroke while always two plungers at a time exert the pressure stroke. In theposition illustrated in Fig. 1, the plunger 7 begins with the pressure Ystroke at the moment when the plunger 7l has finished the same. In the circular sections d--a and 64:0 vthe plungers remain intheJ inner and outer dead-point positions.V As at any moment of thepurnp ro-I tation always a constant number of plungers discharge into the pressure conduit, it fol.-

lows that, since the plunger speed according to-the construction of the pressure curve 1s, uniform, not only during a stroke interval e# but during the Whole delivery period a uniform pump delivery is attained.

The cam of the cam shaft is conical in such a way that within the sectors a-b, b-c, c- -Z, and. d a, the same kinds of curves are maintained but with the difference that-fthe Archimedean s iral branches a-b and c-d run Hatter an the circular arc b-o has smaller radii. Y

If the cam shaft is axially displaced in one or the other directionby means of the adjusting lever 12 andthe screw-.gearing 13, 105 both pumps exert smaller or larger strokes respectively. The cam shaft is locked against yrotation by means ofadisc like spring 14 and groove 15 and thus maintains always the f same positlon with reference to the suction of. consumption. i the lubricant pressure channel is the lubricating groove 20 that leads pressure oil into `and pressure channels in lthe pump casing.I -The plungers will suck during the suction period fuel and lubricant through the admission ports 16 and 16a and the suction channels 17 and 17a and deliver this during the pressure period through the pressure channels 18 and 18EL and through the pressure ports 19 (and 19a, not shown) to the places In communication with the ring channels 21 and 21a and through the grooves 22 and 22 into' the interior 23 of the pump casing 1, Where it is distributed l through the longitudinal grooves 24 into the each other are continuously lubricated in an effective Way 4by the oil under pressure.

charge into the pressure conduit with a uniformI plunger movement. v

'lhe arrangement of the cylinders, either in star shape as illustrated, or in series bef side each other and at. right angles to the cam shaft, or in af circle and parallel around the cam shaft, is also immaterial, all this being appropriate constructional formsof the idea of the present invention only.

The arrangement may, of course, also .be such that the plungers are not arranged'in a rotary drum but in a stationary framing While the camshaft is revoluble; this being obviously understood Without further illustration.

Furthermore, it is not absolutely necessary A that Ithe fuel pump is combined with the lubricant pump in one casing. The same effect is attained if the presure oil of a separately arranged lubricantgpump is in-` troduced-into the casing of a fuel pump;

Furthermore, by a convenient choice 0L the arrangement combined in one casing as illustrated being, of course, preferred for theratio between the oil pressure in the interior of the pump casing and the fuel pres- 25 sure in the C linderS, a continuous slight overflowing of lubricant into the interior of the ump cylinders can take place. Whereas tliereby thevsafety of the pump Working is considerably increased, the oil addition to the fuel in the motor Working is much `desired. Diiiculties, similar to those aforedescribed, in the Working of the fuel pump in the interior of the motor are done awayl `bv saidA oil addition.-4 Particularly, the 8 5 plungers, the cylinder Walls, and the valves are thereby coated with a slight oil dilm and thus sticking valve rods, burning of the valves, and plunger-rino' breakings are effectively avoided. Furthermore, the fuel is prevented by the Aoil in the interior of the p p casing fromA escaping from the pump tirough untight joints of casing parts or through the bearings of the driving shaft.

Of course, in each of the two pump sys- 'stems and in the same or in parallel cylinder planes, further plungers can be used, prQ- yvided that the condition is accomplished: that all said cylinders produce a perfectly uniform pump delivery. In this' case, cam

l0 shafts such as shown'in Figs. 5-8 must be employed. The pump Ic li'nders of the fuel or lubricant system in s. 5 and 6 ar L ranged in one plane, v --d those ,in Figs and 8 in two planes parallel to one another.

For, in these cases, a simple duplication only' and no change ofthe mode of operation forming the subject matter of the presentin- -vention, is required. It is also immaterial how many plungers are actuated ata time ressure curve section of the cam A shaft, it eing essential only for the idea of the 'present invention that at any lmoment always a constant number of plungers dis-i l1. In a plunger pump, the combination of a pump casing, a rotary plunger drum therein comprising a plurality of cam-controlled plungers, and a non-revoluble cam 'shaft acting upon said plungers and having a cam curve designed to create at any moment a pump delivery by a constant number of plungers with a uniform plunger movement. v

2.`A plunger pump as specified in claim 1, in Which said cam shaft is' axially adjustable and thereby adapted vto vary the strokes ofl all said plungers Without impeding the dependence of the latter upon each other and their uniform movement.

3. In a plunger pum as speciiiedin claim 1, means by which sai pumpcasing is continllously`lled with pressure oil during the Working of thepump.

4. In a plunger pump as specified in claim 1, in which said plungersbelong-to a fuel pump' system and toa lubricant pump sys- 'pump system\ and to a lubricant pump syf-ttem; mcansfto .vary the plunger strokes of pumps but it can, for instance, also Y llG tem; a common driving shaft-for both said both said pump systems at a timeiin dcpedence upon one another.

In testimony whereof I have hereunto set "my hand.

IGNTHER scHNEGGE-NBURGER. 

